You can check the version under System -> Rockbox Info.
There are two different "kinds" of latest build: the latest release version (3.6, released in June) and the latest current build, produced every time something changes, which is many times per day. The current builds have a revision number, such as r12345.
If you have 3.6, you may want to try the current build to see if it works better for you. The iPod port is generally extremely stable so even the current builds should be perfectly fine to use.